Location:
Also called false tendons, false chordate and left ventricular moderator
bands among other names, left ventricular bands are fibromuscular
structures in the left ventricle crossing the cavity or simply joining
nearby trabeculations or papillary muscles left ventricle. These bands
are not present in all hearts, but are within the normal variation of
anatomy. They can contain muscle tissue or simple be connective tissue.
Occasionally, they have been observed to contain conduction fibers.

Importance in device delivery:
Left ventricular bands may provide obstacles and potential snag points
while navigating devices in the left ventricle.